Letter flap moistener



July 12, 1960 J. w. BACH ETAL LETTER FLAP MOISTENER Filed April 21, 1958 July 12, 1960 J. w. BACH EI'AL 2,944,511

LETTER FLAP MOISTENER Filed April 21, 1958 s Sheets-Sheet 2 July 12, 1960 Filed April 21, 1958 J. W. BACH EI'AL LETTER FLAP MOISTENER 3 Sheets-Sheet 3 ATTORNEY United States Patent lice Q 2,941,511- LETTER'FLAP MOISTENER John winiauinaehand Robert Peet, Jr., Stamford, and Harry F. Miller, Springdale, 'Conn., asslgnors to fitney-liowes, In'c., Stamford, Conn., a corporation of nelawaie I p 7 Filed Apr. 21,1958, Ser. No. 729,976

Claims. (Cl. 118-243) This invention relates to devices for moistening the gummed closure flaps of envelopes, more generally referred to as letters, preparatory to sealing them for mailing. 7

An object of this invention is to provide a simple and e'flicie'nt letter-flap moistener which will operate on letters which vary in weight, length and width over a wide range.

Another object is to provide such a device which is easy to operate and which is substantially trouble-free.

This and other objects referred to' below have been obtained by a novel combination of means for separating the closure-flap from the body of the letter by bowing the letter transversely andinaintaining the separation by a stripper plate as the letter is advanced to a moistener, and insuring that notwithstanding the bowing of the letter the original flap fold is preserved and no false crease at the flap-fold willbe produced adjacentthe junction of the flap with the body of the letter. Such a false crease 7 would result in improper sealing of the letter and i s undesirable for many reasons.

It is therefore an important feature of the'present invention that the formation of a false crease which might result from the bowing of the. letter is avoided. This is aceomplished by providing on the device suitable surfaces on which the leading end of the letter rides and by which the body of the letter and its closure flap are guided and defiectedl 7 Another feature of the present invention is the provision of simple andconvenient means for applying pressure to the letter so that it properlyfollows the guide surfaces which it engages, whether the 'letter be of normal thickness or thicker or thinner than normal. Such means in the form of the invention illustrated and described herein as exemplary thereof includes a supporting structure overlying the path of the letter and having ashaft extending transversely of the direction of travel of the letter on which there is mounted a plurality of fingers which extend in the direction of travel of the letter and which are yieldingly urged against the body of the letter as it advances.

In the form of the" invention herein illustrated, the flap of the letter is moistened by an applicator mounted o'n the delivering end of the flap stripper plate over which the body-of the'letter rides. Pressure is applied'to the appl-icator (to press it against the flap.) through'the medium of the letter passing over the plate. To do this, an'additional spring-operated finger is mounted on the transverse shaft carrying the other fingers and this additional :finger is extended to engage the portion of the letter on the plate ata point substantiallyover the applicator. I y I Qther features. and advantages will hereinafter appear.

- For the purposes of illustration and explanation, the invention is shown in'detail in its preferred formin" the accompanying drawings, wherein: a g V Fig. 1 isaperspective view of the letter flap moistening device of the present invention showing itapplied to r a post-age meter machine with parts'of the casing removed; Fig. 2 is a fragmentary end view of the receiving end 2,944,511 a V "Patented J'illy 12,1 960 an advanced stage in: its travel through the machine at which time the'fla'p-foldi's depressed into engagement with a lateral or back guide;

' Fig. 4 is a view similar to Figs. 2 and 3 showing the letter at 'itsstill runner advanced position; and showing a pressure finger for applying pressure at a pointo'ver' a'= moistener applicator;

' Fig. 5 is a perspective view like Fig. 1,. but showingthe letter in the position illustrated-in Fig. 2 in which the letter is bowed and showing only the finger forbowing the letter;

Fig. .6 is a: view' like Fig. 5; but showing the letter in the positionishown inFig. 3, with" only the finger for restoring the flap-foldbeing shown; w Fig. 7' is a view like Figs. 5' and 6,,but showing the letter in the position shown in Fig; 4, with only the fingerfor applying pressure to the applicator shown;

Fig. -'8,is a topplan view of the moistening device' of the presentinvention showing a Ie'tterbeing advanced through'the device; and Fig. 9' is a longitudinal sectional view taken on theline 9:-9 of Fig. 8:. a Y

As shown in-Fig. 1-, the moistening device of the pres-- entinvention is incorporated in a postage metermachifle (shown fragmentarily) including ameter casing: 10 con rainingmechanism which prints a postage stampji'mpression on the letter; It also includes a'framework a and the table 12 through which theletters' pas's.

The moistening device of the present invention is 1'0- eated at the entry end of the passage 13 and comprises a housing 1 4 having a top surface substantially in the plane; of the table' 12;. The housing encloses a. reservoir 15 for moistening fiuid and has a wick 16 contained therein (Fig; 9),. throughwhich moisture is attracted to its. exposed end by capillary attraction; Mounted on theupper portion ofthe housing- 14 within. the passageway is a flap stripper plate -17. flap moistening. brush 1 9 supportedby a plate 18 and is hinged at--18a to the delivery end of the stripper plate'17, the brush restingon a portion of the wiclc 16. In passing through the machine, the flap F of a letter L passes .under the'stripper p'late- 17, in a manner described below, and between the brush 19 and the underlying supporting surface-20 forming part of the housing 14 so that moisture picked up by the brush 19 from the exposed moist end of the wick 16 will be transferred to the upwardly facing gummed inner surface Gof'the letter flap. a The stripper plate 17 is secured to the housinglflalong the front edge portion '21 thereof so that the working'por tionprojects into thepassageway 13 and isotherwise spaced from the upper surface 20 of the housing. In the embodiment of the invention herein illustrated asexemplary thereof, the letters L are hand fedendwise throughthe moistening, device with the face of the letter upward and with the ,edge2'4. of the flaprfoldin engagement withfla back guide surface 23 of a bracket 30. "The ieadingiowe'r surface of the letter is initially supported onthesurface of the stripper plate 17. The entering or stripping edge 26 of the stripper plate 17 is beveled to a dull kjnife edgeand ,slopesofl as it extends inwardly and 1 s'of that initially while the. bodyof the letter 1's bei g supported by the surface of the stripper plate, the flap of the letter unsupported but'nevertheless remains flaragainst-thebony of the-letter;

Since it is desired to moisten the gummed inner surface 3 G of theletter flap by the brush 19, the leading edge of the flap must be separated from the body of the letter so that it can pass under the stripper plate 17 while the body of the letter passes over it.

To accomplish the stripping of the leading edge of the flap from the body, the present invention applies downward pressure to the letter in the vicinity of the flap-fold when the leading edge of the letter reaches a predetermined point in its advancement. For this purpose, a pivoted pressure finger 27 is provided in the path of the leading edge of the letter. The pressure finger 27 is carried on a shaft 28, mounted in an overhanging arm 29 of the bracket 30. One end of a spring 31 on the shaft 23 engages the finger 27 and yieldingly urges its end downwardly.

As the leading edge of the letter engages and moves beyond the finger 27, as in Fig. 8, the finger pressure, which occurs short of the knife edge, causes the letter to be bowed sufficiently to cause the flap to move away from the body of the letter so that the knife edge portion 26 of the stripper plate may pass under the flap. The flap is thus maintained separated from the body of the letter so as to pass under the brush 19. The tension of the spring 31 is so adjusted as to produce the required amount of bowing of the letter.

As a result of this bowing of the letter, the angle between the body of the letter and the flap at the flap-fold is such that restoration of the flap-fold portion to its normal position could result in the formation of a false crease at the fold. That is, a new crease could result between the fiap and the body of the letter which would converge outward from the leading to the trailing end of the letter leaving an undesirable gap between the body of the letter and the flap edge at the trailing end.

To avoid such false creasing possibility, the present invention provides for a spring urged finger 32 on the shaft 28 which is positioned to engage the letter at a point between the finger 27 and the back guide surface 23. The finger 32 is arranged so as to yieldingly engage the longitudinal marginal portion of the letter. As the letter advances, its leading edge is engaged by a curved surface 33 of the finger 32 which tends to depress the longitudinal margin and move the flap-fold downwardly to substantially its normal position, as shown in Fig. 3. To facilitate this bending down of the longitudinal flap-fold margin of the letter, the stripper plate 17 is provided with an upwardly projecting curved lug 34 in line with and ahead of the finger 32, as best seen in Fig. 2. The combined pressure of the finger 32 and the curvature of the lug 34 causes the body of the letter to be drawn around the lug while the flap edge assumes a somewhat normal position against the back guide 23. The flap takes a position under the free inner edge 22 of the stripper plate in a substantially horizontal position.

These operations on the letter continue while the letter is advanced manually and during the printing part of the operation thus maintaining the flap edge of the envelope in its normal fold relation throughout a flap moistening operation. While printing, the letter is advanced under power by a printing drum and impression roller in a known manner.

To accommodate letters of varying thickness the finger 32 is providedwith a .flat spring having two spring elements a longer spring element 36 and a shorter spring element 37 which successively come into operation. A letter of normal thickness will cause the finger 32 to be engaged by the longer or weaker spring element 36, Whereas, a letter .of greater than normal thickness will cause the finger 32 to be raised higher than normally and be engaged byboth the spring element 36 and the spring element 37. The advancement of the letter past the moistening brush 19 causes the gummed portion G of the flap to be engaged and moistened by the brush 19 While the body of the letter rides over the stripper plate 17.

In order to conveniently apply pressure on the brush so that the flap is properly moistened, the present invention further provides a finger 38 carried on the transverse shaft as to engage the body of the letter thus applying pressure therethrough to the brush supporting plate 18 and to the brush 19. The opposite side of the flap is backed up by the surface 20 of the housing 14, as above explained. The finger 38 is yieldingly urged toward the letter by a spring 39. p 7

After the flap has been moistened and the letter has passed beyond the brush, pressure to seal the flap of the letter may be provided by any suitable means. When the device is used with a postage meter machine as shown, sealing pressure is provided during the normal rotary printing operation. The stacking of the letters one upon the other further adds to the effective sealing of the flaps.

What is claimed is:

l. A device for moistening the gummed closure flaps of letters comprising a back guide for the flap-fold edge of a letterbeing advanced through the device; a flap stripper plate in the path of travel of the letter to be interposed between the flap and the body of the letter, said stripper plate having an entering end and a delivering end; a moistener at the delivering end of the stripper plate to apply moisture to the gummed inner surface of the flap as the letter advances; means at the receiving end of the device for bowing the letter transversely whereby a space is opened between the leading edge portion of the flap and the adjacent portion of the letter body, the stripper plate being positioned to enter said space; and means subsequently engaging the body of the letter adjacent the flap-fold edge for deflecting the flap-fold of the bowed portion of the letter to a position engaging the back guide so as to avoid the formation of a false flap-fold when the flap is moistened and pressed against the body of the letter.

2. A device for moistening the gummed closure flaps of letters compnising a frame; a stripper plate for supporting letters as they are advanced through the device, said plate being supported on the frame solely at its exterior edge portion and spaced elsewhere from the frame to provide a clear passage beneath it for the letter flap; a back guide on the frame adjacent but spaced from the interior edge of the plate and positioned for engagement with the flap-fold edge of a letter to guide the letter in passing through the device; a moistener supported on the delivering end of the stripper plate, the moistener including an applicator positioned to engage the gummed surface of the flap of a letter, the stripper plate having an entering edge to separate the flap from the body of the letter so that the flap passes under the stripper plate and the moistener applicator; means for bowing transversely the flap-fold edge portion of the letter to raise the flap-fold and space the flap from the body of the letter as the letter approaches the entering edge of the stripper plate; a projection on said plate about which the flap edge body portion of the letter will flex; and means for depressing the flap-fold edge of the letter around said projection to restore it to engagement with the back guide and avoid a false crease being formed at the flapfold.

3. A device for moistening the gumrned closure flaps of letters comprising a frame; a stripper plate for supporting letters as they are advanced through the device, said plate being supported on the frame solely at its exterior edge portion and spaced elsewhere from the frame to provide a clear passage beneath it for the letter flap; a back guide on the frame adjacent but spaced from the interior edge of the plate and positioned for engagement with the fiap-fold edge of a letter to guide the letter in passing through the device; a moistener supported on the delivering end of the stripper plate, the moistener including an applicator positioned to engage the gummed surface of the flap of a letter, the stripper plate having an entering edge to separate the flap from the body of the letter so that the flap passes under the stripper plate and the moistener-plateto the applicator; means for bowing transversely the flap-fold edge portion of the letter to raise the flap-fold and space the'flap frorn the body of the letter as the letter approaches the entering edge of the stripper plate; means for depressing the flap-fold edge'of surface of the flap, of a plurality of pressure applying elements mounted above and engageable with the upper the letter to restore it toengagementjwith the back guideto avoid a false crease being formed'at the flap-fold; means for applying pressure to the body of the'letter as it passes over the moistener plate to applypressure to the latter through the letter and hence to cause the ap-I plicator to press against the gumrned surface of the flap; each of said means being pivotally and yieldably supported on an axis perpendicular to the back guide,-

4. In a device for moistening the gummed envelope closure flaps of letters as the envelope portion thereof surface of the letter as it moves therepast, one element to I effect bowing of the letter whereby the flap openssufficiently to assure'stripping engagement of the stripper plate therewith, one element to depress" and force the flap fold edge against the back-guide a avoid a false crease,

' and one element to apply "pressurethrough the body of with its flap down is moved endwise, across a moistener applicator, a supporting surface for the envelope comprising a flap stripper plate having a stripping edge shaped to enter behind the flap, a back guide engageable by the flap fold edge of the envelope, means to bow the envelope to cause the flap to separate from the back thereof sufficiently for the stripping edge to effectively enter therewith its flaps down is moved endwise across a moistened applicator, a supporting surface for the envelope comprising a flap stripper plate having a stripping edge shaped i to enter behind the flap, aback guide engageable by the -flap fold edge of the envelope, means to bow the envelope to cause the flap to separatefrom the back thereof suffic'iently for the stripping edge to efiectively' enter there- 1 under, an upwardly projecting lug onlthe stripperplate same around the 'projecting lug andxagainst the 'back guide to thereby maintainthe edge ofthe'flap fold in engagement with the back guide and avoid a false crease at the flap fold. i

6. In a device for moistening the gurnrned envelope,

the letter and'againstithe moistenerbrush to effectadequate'moistening of the gummed portion of the flap.

8,. In a device for moistening the gummed closure flaps of letters-passed endwise therethrough, the combination with a frame havinga back guide engageable by the flap edge of the letter, a flap stripper plate in the path of the flap, and a moistener brush in the path of the 'gummed surface of the flap; of three spring urgefd pressure apply ing fingers engageable with the'upper surface of the letter v as it moves therepast, a shaft transversely positionedrelative to the direction of letter movement, a supporting arm for said shaft extending from the back guide a projection on said stripper plate engageable by'the flap fold, one finger to eifect bowing of the letter whereby the flap opens sufliciently to assure stripping engagement of the stripper plate therewith, one finger to depress the'flap fold edge around the projection and against the back guide to avoid a false crease,,and one finger to apply pressure through the body of the letter and against the moistener brush to effect adequate moistening of the gummed portion of 9.1 In a device for moistening the gummed closure flaps of letters passed endwise therethrough, the combination with a frame having a back guide engageable by the flap edge of the letter, a flap stripper plate inthe path'of the flap, and a moistener brush in the path of the gummed surface of the flap; of a'shaft ,projecting'from the back guide above and across the path of letter movement, a

spring pressed finger having one end pivoted onsaid shaft and-its'free end ,engaging the letter to effect bowing at 1 the flap area thereof, whereby the flap opens suificiently toraise the fold edge portion of; fil envelopeias'it passes I y, vthereover, and a springurged'fingei 'havinga'eamshaped end engagingtheraisedj fold edge to efliectivelyforce :to'assure stripping engagement of the stripper plate therewith,{ and anotherlspringpressed, finger having one end pivoted onithe shaft and'havirigits free end engaging the 5 letter near the'fold edge thereof to depress same and force closure flaps of letters as the envelope portion thereof with its flap down is moved endwise across a moistener applicator, a supporting surfaceforvthe envelope comprisinga fiap stripper plate having a stripping edge shaped to enter behind the flap, a back guide engageable envelope to cause the flapto separate; from the back tively force same aroundthe projectinglug and-against by the flap fold edge of the envelope, meansto how the the flap fold edge against the back guide, whereby a false crease isavoided.

' p g '10. In a device for moisteningthe gummed closure flaps of letters "passed endwise therethrough, the combination with-a frame having aback guide engageable by the flap edge ofthe letter, a flap stripper plate in the path of the flapand a moistener brush in the path of the gummed surfacetof the flap; of a shaft. projecting from the back guide above and across the pathof letter movement, a

thefiap area thereof, whereby the flap opens suificiently 1 to assure stripping engagement of the stripper plate therewith, .a raised portionfon-the stripper plate inthe path of the-fo1d"iend portion of the letter, and another spring V pressed-finger having one. end pivoted on the shaft and 1 having its free end engaging an area of the letter near fthe fold edge thereof to depress said areaaround the g the back guide to therebymaintain the edgeof'the'flap fold in engagement with the'backf guide and eluding a variable pressure springassociated with said-fingerto 1 effect light pressure {when envelopes with lighter weight contents arejmoved through the moistening position raised portion and force the flap fold edge againstthe back guide; whereby a false crease is avoided.

heavier pressure-when envelopes with heavier weight 'con tents are moved through the moistening position, '.,where- 7.. 111 a device'formoistening the gummed closure of letters passed endwise therethrough, the combination References (fitted the file of this patent 1 UNITED "STATES PATENTS Great Baitain Apr. 24, 1939 Talbot Mar. 24, 1896 

